The permissibility of a single closing salam in prayer, and when it is prescribed for the follower to say the salam. (The issue of following the imam)

The Shaykh : ... This concerns the salam. It is known in this country that those following the imam do not exit the prayer with the salam until the imam has finished his second salam. This appears to me to be contrary to the Sunnah, and I say "appears" because I mean what I say. This is because the Sunnah is sometimes explicitly stated such that the general public and the specialists share in its knowledge, while there are other matters in which there is no sharing between the general public and the specialists, or in their knowledge of them, and they are specific to the specialists. Our issue here is of this kind. It is established in the Sunnah that the Prophet (peace and blessings be upon him) used to say the salam twice, to the right and to the left. But it is also established that at times he would restrict himself to a single salam. One who knows this Sunnah and the one before it will derive a legal ruling in his mind that is not explicitly stated, and yet we say the Sunnah is thus, by derivation and citation, not by explicit text. What is this ruling? When does the one praying, whether he is an imam or a follower, exit the prayer, with the first and last salam together, or does he exit the prayer with the first salam, such that if he does not say the last salam, he has finished his prayer, his prayer is valid, and at the same time he has applied the hadith of his Prophet (peace and blessings be upon him) in prayer when he said: Is the salam here interpreted as saying the salam twice, or as saying the salam once? The answer, based on the previous detail, is that he (peace be upon him) sometimes said the salam twice and sometimes said the salam once. So if the one praying says "Peace be upon you," is his prayer valid or not? His prayer is valid. Why? Because he exited the prayer with the salam. But if we did not have the second hadith that the Prophet (peace and blessings be upon him) sometimes restricted himself to a single salam, then the previous legal ruling would be reversed: "Peace be upon you" would invalidate your prayer because you have not yet exited the prayer. But since it is established that the Prophet (peace and blessings be upon him) said the salam once, you have now exited the prayer, and the prayer has ended with its prohibition and its salam. If that is the case, and you are ever tested with an imam like me—I do not say he will surprise you, but he may surprise you by saying "Peace be upon you" and then remaining silent—what do you do? Do you wait? Do you wait for the second salam? Why? Because that is what you are accustomed to. And now we have seen this with the one who used to convey to you my transitions, my takbir, and my salam, where he did not say "Peace be upon you" to the right and left until after I had said my second salam. So he reminded me of this reality, this reality. So it was obligatory for me to alert you to this reality that it is contrary to the Sunnah. Do not wait for the imam to begin the second salam and finish it before you start. No, if he says "Peace be upon you," say "Peace be upon you." Then if he repeats it, you repeat it after him, with him. And what confirms for you this general principle that he (peace and blessings be upon him) established and set down by his saying: Then he detailed it, and may Allah have mercy on you. Then he detailed it for us in detail, saying: The point of this hadith, regarding our issue here, is We return: "If he says the salam, then wait" or "If he says the salam, then say the salam"? So, "If he says the salam, then say the salam." We understand from the language that when an imam says "Peace be upon you," and one of the pure Arabs, before foreign influence entered them, wants to express what he heard, would he say "The imam said the salam," or "Wait for your second salam"? He would say "The imam said the salam." So, on the basis of his (peace be upon him) saying: We say: If he says the salam, then say the salam. If he says the first salam, say the salam. If he says the second salam, say the salam. And if he does not say it, do not say it. Because this is the meaning of following in the previous hadith. And I apologize, and I am sorry to say.